Most factory ammo will shoot bullets slower in ones own firearms as their barrels' bore and groove diameters are typically larger than the SAAMI spec test barrels often used to test ammo.

Safe reloads may well be the same thing. And the barrel published loads were developed with will be different than yours. So are the primer, powder and case lot numbers and these also make differences in muzzle velocity. So is case neck tension on the bullets. To say nothing of the pressure measuring methods so often used in published data; it could be way too high for safety.

Be patient with your bullet's speeds. They don't need to win the race to the target, but arriving all at the same place is great. Who'll really know if they got there 100 fps slower than someone elses that are spread all over the place.

If velocity for a given bullet needs to be as fast as possible, use the biggest case that can use it, then use as much powder as you want under it. How safe it is depends on your overall objectives in life.

__________________
US Navy Distinguished Marksman Badge 153
Former US Navy & Palma Rifle Team Member
NRA High Power Master & Long Range High Master
NRA Smallbore Prone Master